Hi, I had the same issue and after getting nowhere trying to contact PayPal and no luck in the community or Google, I finally managed to resolve it myself by figuring out it was an IPN issue (Instant Payment Notification) Hopefully this works for you too.
Sign into your PayPal business account and go to 'Account Settings' (Drop down menu from your account name in the top right-hand corner) then click on 'Notifications' from the left-side menu, click on 'Instant Payment Notifications'. Click 'Update' - Now, from here, make sure that the Notification URL is correct - it should read something like https://YourWebAddress/?give-listener=IPN (instert your website address between the forward slashes if not present) and ensure that Message Delivery is set to Enabled. Finally click on Edit Settings and hopefully your payments will now go through with no issues.
